Fines agglomerator

ABSTRACT

Apparatus for agglomerating fine solid particles including a rotating frusto-conical housing into which the fines and a molten slag are introduced so as to efficiently form agglomerated members.

O United States Patent 1 [111 3,756,761 Fernandes Sept. 4, 1973 [5 1 FINES AGGLOMERATOR 2,828,190 3 1958 King 425 222 x 3,210,772 10/19 5 tirlin 425/222 X [75] Invent Henry mamas, d 3,206,528 9/1965 Coom s et a1... 425/222 x Conn- 3,345,683 10/1967 Eirech et al. 425 222 [73] Assignee: Combustion Engineering, Inc.,

W d C m Sm Rrims m.i4 br!ESP n Filed: 9, 1971 A ttorney-Eldon H. Luther, Robert L. Olson et al.

211 App]. No.: 213,343 I [52] US. Cl 425/222, 264/117, 425/332 [57] ABSTRACT [51] Int. Cl B29b 1/02 [58] Field of Search 425/222, 332, 333; A aratus for agglomerating fine solid particles includ- 264/117, 8, 49; 65/144, 19, 21, 18 ing a rotating frusto-conical housing into which the fines and a molten slag are introduced so as to effi- [5 6] References Cited ciently form agglomerated members.

UNITED STATES PATENTS ll/l96l Rolfsen 425/222 4 Claims, 2 Drawing Figures FINES AGGLOMERATOR BACKGROUND OF THE INVENTION One of the problems facing utilities, crushing plants and many other industries, including the refuse incineration industry, is that fines are produced which are a very serious environmental problem. The dust or ash liberated during the processes and the final disposal of the inert solid material from these processes, even though sterile and not a sanitary nuisance, is an air and water pollution problem.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side view of a fines agglomerator constructed in accordance with the invention; and

FIG. 2 is a view taken along lines 2-2 of the fines agglomerator.

DESCRIPTION OF THE PREFERRE EMBODIMENT Referring to FIG. 1, l denotes a frusto-conical housing of a fines agglomerator. The housing has a front inlet end 12, and a rear outlet end 14. The outlet end 14 is supported slightly lower than the front end, so that gravity causes any material placed in the housing to move from the inlet to the outlet.

Secured to the open front end of housing 10 is a channel or trough 15, into which fines, such as flyash, are fed by feedscrew l6. Molten slag is also deposited in trough 15 by the slag spout 18. The fines in trough 15 are slightly wetted by means of a water spray nozzle 20, in orderto keep the dust level down and to offer a quenching action as the molten slag contacts the fines.

This also insures a stronger agglomerated and product.

The slag spout 18 is moved back and forth in the direction of the axis of housing 10 by eccentric 22 so that the slag is distributed over the full width of thebed of fines in trough 15. The laying on of the molten slag. in

this manner, when coupled with the basic rotation of the housing (described below), prevents large, oversize agglomerates from forming and plugging the unit.

The slag spout l8'is heated by means of a gas torch 24. This is needed to maintain the slag in a molten state during startup and shutdown, and may even be necessary on a continuous basis. The slag spout 18 is replace-'- able, and is made of a refractory lined metal tube.

The front end of housing 10 is supported by a pair of rollers 26, 28, best seen in FIG. 2. The rear end of the housing is supported by a similar pair of rollers 29. Motor 32, through gear drive 30, causes rotation of the housinglo."

Ahead of outlet end 14 is a bar screen portion 34, through which undersized agglomerates or remaining fines drop out of the housing 10 onto a conveyor 36. This conveyor can transfer these small particles back to storage bin 35 (FIG. 2) for recycling. The round shaped agglomerates are discharged through outlet 14 onto a conveyor 40. These agglomerates are a high consistency end product, and can be disposed of in numerous profitable ways. It can be used as aggregate for concrete and asphalt mixes for road and construction work. Since it is a dense, sterile, stable material, it can also be used as an improved landfill material, or it can be readily stored for use at a later date.

A stationary dust cover 42 which covers a major portion of the inlet 10 helps to keep down dust. This cover can be supported from above by bars 43. Another stationary dust cover 44 is utilized to cover the upper portion of bar screen 34.

The operation of the agglomerator should be readily apparent from the above. Fines and slag are deposited in trough 15. The molten slag is deposited downstream of the fines in the direction of rotation, as seen in FIG. 2. The slag, in falling on a moving bed, form droplets which agglomerate with the fines and fiyash in the bed. The rotating housing causes these materials to agglomerate into a dense ball, and the slope of the housing causes the ball tomove from the inlet end to the rear of the housing, 'where the screening bars separate out the undersized agglomerates and any remaining fines. The end product agglomerate is discharged from the outlet.

As mentioned earlier, the fines agglomerator of the present invention could be used on various materials. The fines could be flyash separated from the exhaust gases of a refuse incinerator or other furnace, such as a coal fired power plantrThe incinerator or furnace could also be the source of the molten slag. Another example might be dust separated from the exhaust of a crushing mill. The molten slag could come from a furnace charged with fuel and a low melting point, nonmetallic mineral, such as limestone, or it could be tar or asphalt. t The advantages of the present fines agglomerator are that a strong aggregate of controlled size is produced. There is no disposal problem. As the material proceeds through the housing, the less firmly held fines are broken down and either meet the size criteria or are separated through the bar screen and returned for a second agglomeration cycle. The dust generated by the process is controlled without introducing it to the environment.

' Friability is overcome by the tumbling action caused by the rotating housing. If the agglomerate is weak, it breaksup and is screened out for return with the fines.

The: pellitized end product can also be stored outside because of its good weathering properties.

What is claimed is:

1. Apparatus for agglomerating fine solid particles including a-frusto-conical housing, said housing having a circulaiicross section, the-housing having aninlet end and an outlet end, means forrotatably supporting thev housing such that the inletend is slightlyhigher than the outlet end, means for rotating the housing trough means secured to the inlet end of the housing, first means 'for introducing fine solid particles into, the trough means, second means for introducing a molten material into the trough means, third means for intro; ducing a liquid to the trough means, said first means being positioned upstream of said second means in a rotational sense, a portion of the housing in front of the outlet end being made of screening means, through whichany particles below a given size will be removed for continuously moving the second means back and forth, so as to deposit the molten material across the entire width of the trough means.

4. The apparatus set forth in claim 3, wherein said housing inlet end is larger than the outlet end. 

1. Apparatus for agglomerating fine solid particles including a frusto-conical housing, said housing having a circular cross section, the housing having an inlet end and an outlet end, means for rotatably supporting the housing such that the inlet end is slightly higher than the outlet end, means for rotating the housing trough means secured to the inlet end of the housing, first means for introducing fine solid particles into the trough means, second means for introducing a molten material into the trough means, third means for introducing a liquid to the trough means, said first means being positioned upstream of said second means in a rotational sense, a portion of the housing in front of the outlet end being made of screening means, through which any particles below a given size will be removed from the housing, and means positioned adjacent the outlet end for receiving the agglomerated particles being discharged from the housing.
 2. The apparatus set forth in claim 1, including means for heating the second means.
 3. The apparatus set forth in claim 2, including means for continuously moving the second means back and forth, so as to deposit the molten material across the entire width of the trough means.
 4. The apparatus set forth in claim 3, wherein said housing inlet end is larger than the outlet end. 